Project Summary/Abstract TBI (traumatic brain injury) is the leading cause of long-term disability and death for individuals under the age of 45. Over 2.5 million cases of TBI are reported each year in the United States, with ~3-5 million individuals living with TBI-related disabilities. About 75% of patients diagnosed with TBI are classified as mTBI, which can be difficult to diagnose, as history is often incomplete and symptoms are nonspecific and overlap with a broad range of neuropsychiatric disorders. Although most patients with mTBI make a full recovery, as many as 20% do not. Individuals who experience multiple mTBI are at increased risk of persistent post-injury symptoms and long-term complications, including serious sequelae such as chronic traumatic encephalopathy (CTE). Simple interventions such as removing the patient from risky environments may prevent these complications by allowing time for the brain to heal and preventing further injury. Management of mTBI in the field, in the emergency department, and even in the primary care office is complicated by the absence of a safe, simple, and sensitive tool to assist in making the diagnosis and in tracking a patient's recovery. Rebion has produced a portable device ? with compelling preliminary, pilot data ? for identifying and monitoring traumatic brain injury in patients by way of a retinal scan. The device, which has FDA clearance (DEN 130051) for identifying misaligned eyes in children, has shown to accurately identify acute episodes of mild traumatic brain injury (mTBI) and track a patient's recovery that matches the medical diagnosis. The device is called HITT, the Head and Intraocular Trauma Test device. Grant support is being requested to support further development of the HITT device so that it can be field deployable in a larger-scale clinical study. The data that has been collected to date has led to a better understanding of the algorithm and electronics requirements that will be needed to make the HITT device usable ?and interpretable? by a lay user. Successful execution of project milestones will lead to pivotal clinical studies that will be vetted by the FDA. Data from the studies will be submitted to the FDA for consideration of market clearance of the HITT device.